Vacuum cleaner for blackboard erasers



' Nov. 11, 1941. c. H. HOFFMAN 2,262,724

VACUUM CLEANER FOR BLACKBOARD ERASERS Filed Feb. 28, 1940 I. mmhmmhm 15m W W.

Patented Nov. 11, 1941 VACUUM CLEANER FOR BLACKBOARD ERASERS Charles H. Hoffman, Canton, Ohio, assignor to John J. Cormier, Clarence I. McAllister, and H. Clifton Graybill, all of Canton, Ohio Application February 28, 1940, Serial No. 321,221

1 Claim.

The invention relates to vacuum cleaners, and more particularly to a cleaner especially adapted for cleaning blackboard erasers such as are commonly used for erasing blackboards in schools and the like.

The object of the improvement is to provide a device arranged to be attached to the usual socket of an installed vacuum cleaning system, such as Tuec or Spencer, or to any other suitable suction or vacuum apparatus, and provided with a perforate serrated portion over which the eraser may be rubbed to loosen the chalk dust therefrom, permitting the dust to be drawn into the vacuum system, whereby the device may be used in a school room or the like without inconvenience or discomfort to those in the room, as no dust will be permitted to escape into the room.

Another object is to provide an eraser cleaning device of the character referred to comprising a housing having an open top side with spaced, sharp edged bars across the same, and an axially disposed outlet neck communicating with one end of the housing and adapted to be inserted into the usual socket of an installed vacuum cleaning system, or the like, and a damper in said outlet neck arranged to be operated to close the outlet neck when the device is not in use.

- The above and other objects may be attained by providing an eraser cleaning attachment comprising a housing having one open side provided with spaced bars having sharpened edges for rubbing contact with the eraser to loosen the chalk dust therefrom, a tapered neck being formed at one end of the housing and communicating with the interior thereof, for insertion into the usual socket of a vacuum cleaning system or the like.

An embodiment of the invention is illustrated in the accompanying drawing, in which Figure 1 is a plan view of the improved vacuum cleaner for blackboard erasers, showing the same inserted into the socket of a vacuum cleaning system;

Fig. 2, a section taken substantially on the line 2-2, Fig. 1; and

Fig. 3, a transverse section as on the line 33, Fig. 2.

Similar numerals refer to throughout the several views.

The improved eraser cleaner to which the invention pertains, may comprise the housing II! which is substantially U-shaped in cross section, as best shown in Fig. 3, closed at its outer end as by the end wall I I, and provided at its inner end with a slightly tapered neck I2 communicating similar parts with the adjacent end of the housing, and adapted to be inserted into the usual socket I3 of an installed vacuum cleaning system such asthe Tuec or Spencer system, or to any other suitable vacuum or suction producing apparatus.

If desired, the reduced neck may be inserted into a socket such as shown at I3, communicating with an ordinary flue where it is not possible to have access to the ordinary vacuum or suction producing apparatus.

A series of transversely disposed spaced bars I4 are located across the upper open side of the U-shaped housing to provide a rubbing surface for the erasers to be cleaned.

These bars are preferably located at a distance spaced below the upper edges of the side walls of the housing, forming guide walls I5, between. which the eraser may be reciprocated, thus providing means for properly guiding the eraser as it is rubbed over the bars I4, and preventing any chalk dust loosened thereby from escaping at either side of the housing.

In order to easily loosen the chalk dust from the eraser, the upper edges of the bars I4 are preferably sharpened as shown at It, and this may be best accomplished by forming the bars of triangular cross sectional shape, as illustrated in Fig. 2.

When it is desired to clean blackboard erasers upon the device, the tapered tubular neck I2 is inserted into the socket I3 of the vacuum system, or connected to any other suitable vacuum or suction producing means, as above described, the device being in the position shown in the drawing with the triangular bars I4 on the top side thereof.

The eraser to be cleaned is then placed upon these bars, between the guide walls I5 and rubbed briskly longitudinally of the device.

As the pad of the eraser is rubbed over the sharp edges of the triangular bars, the chalk dust will be loosened therefrom, and withdrawn through the housing and tubular neck I2 into the vacuum system, thus preventing any dust from escaping and flying around the room, and making it possible to quickly and easily clean the erasers in the school room without discomfort or inconvenience to those in the room.

In order that the suction may be cut off when the device is not in use, a damper H, which may be of the butterfly type, as illustrated, may be located in the outlet neck I2, being mounted upon the transversely disposed rod or shaft I8, journaled through opposite side walls of the outlet neck and provided at one end with a handle or having an open top side, spaced, triangular bars located transversely across the housing at a point slightly spaced below the upper edges of the side walls of the housing, so that the upper portions of said side walls form longitudinal guides between which an eraser may be reciprocated upon said triangular bars, an end wall closing one end of the housing and a tapered; outlet neck extending longitudinally from the other end of the housing for insertion into a socket of a vacuum producing apparatus.

CHARLES H. HOFFMAN. 

